The steels supporting the new loft floor bear into the party walls and until the neighbours undertake loft conversions this will be a significant heat loss. The beam ends have been encased in Purneit (a structural insulation left over from another job) with 10mm of Spacetherm blanket behind. Without going to the expense of 3D thermal bridge calculations it’s impossible to determine the improvement but simple U value calculations suggest both the Spacetherm and Purenit reduce the heat loss by a factor of 3. The black paint is Blowerproof which provides the airtightness which is especially critical here as the brickwork is thin and weak. The second image shows where the Purenit has been routered to seat the steel bearing plate with the Spacetherm behind
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